7. Project Summary/Abstract: Cancer immunotherapies tailored to elicit the protective capacity of CD8+ T cells have yielded monumental advances in the treatment of malignancy. However, the immunosuppressive nature of the tumor microenvironment limits intratumoral accumulation and function of CD8+ T cells, contributing to treatment resistance and cancer progression. Therefore, enhancing the ability of CD8+ T cells to infiltrate tumors, accumulate in situ, and rapidly kill tumor cells will yield more effective immunotherapies. We have recently identified transcription factors regulating the differentiation, localization, and function of long-lived CD8+ T cells residing in healthy non-lymphoid tissues, referred to as tissue-resident memory cells (Trm). In connection, tumor-localized T cells share many similarities with Trm, including overlapping transcriptional programs and differentiation requirements. This is the basis for this K99/R00 application, in which I propose to leverage the molecular signals controlling the differentiation of Trm to improve the function of tumor-specific T cells. To this end, I propose the following aims: Aim 1: Determine if Trm-fate specifying transcription factors regulate intratumoral accumulation and function of adoptively transferred CD8+ T cells. I have identified an unappreciated role for the transcription factor Runx3 in instructing residency of highly functional CD8+ T cells in healthy non-lymphoid tissues as well as tumors. I will determine if additional Trm-fate determining transcription factors similarly regulate CD8+ T cell accumulation and function in solid tumors. Aim 2: Predict and validate transcription factors regulating tumor-resident CD8+ T cell differentiation and function. Through utilization of an innovative computational approach integrating transcriptomic data and epigenetic profiling, I will predict and functionally validate transcription factors key to CD8+ T cell accumulation and function in solid tumors. Aim 3: Determine if Trm-programming enhances chimeric antigen receptor (CAR)-T cell efficacy in solid tumors. CAR-T cells have emerged as a novel treatment modality for hematological malignancies. However, the utility of CAR-T cells in solid tumor settings has been less effective. We propose to enhance CAR-T cell function and accumulation in solid tumors through targeting Trm-fate- specifying transcription factors in both human and mouse CD8+ T cells. We have strategically developed an integrative technical and non-technical training plan, including learning the principals and approaches of histology, relevant computational methodology, and CAR-T cell biology. The overall goal of this grant and the proposed training is to obtain additional skillsets and expertise that will ultimately lead to the securement of an independent academic position in the field of Cancer Immunology, related to but distinct from the research of my mentor. An integrated technical and conceptual training plan will be carried out in the laboratory of Dr. Ananda Goldrath at the University of California San Diego, which fosters an academic atmosphere with abundant collaboration, cutting-edge research, and extensive resources for career development and training.